Method of revivifying clays



Patented Mn. 1,

UNITED STATES BALIK C. POLLOCK, LONG BEACH, CALIIOBNIA, ASSIGNOB TO UNION OIL GUITAR! .0]? CALIFORNIA, 0! L ANGEIJIS, 1 OOBPOMTIOI 0] CALIFORNIA rAraNr orrica I 351121101)' Oil:@IQIVIV'JIIWIIG Io sawin This invention refers to a process for recovering cla s which have been used in decolorizing oi s. It has become usual intreatment of lubricating'oils to treat the acidtreated oil with clay to obtain the desired color for the oil. Sometimes the clay is used both as a neutralizing medium and as a dccolorizing medium. Clay is also used inthe. treatment of gasolines, kerosenes and other 10 light oils, simultaneously with or subsequent to acid treatment to obtain the required color.

I have found that if the used clay is calcined atan elevated temperature in the neighborhood of 1200 F., the clay can be used again. However, the limit is soon reached when the calcination of the used clay does not rcvivify it. In other words, there is a limit to the number of times the clay can calcined and reused.

I have discovered that the deleterious product in the clay, which limits the number of re-calcinations and'revivifications, is the acid sludge which the clay has adsorbed when it was used to treat acid treated oils. These acid treated oils contain suspended sludge particles which are adsorbed by the clay.

I have found that if these acid sludge constituents are substantially entirely removed the clay can be used over and over again,

so ractically without limit, the only limitation ing the gradual loss of clay due to solution and mechanical handling of the clay.

It is, therefore, an object of my invention to so treat clay which has been used in treat ing oils containing acid slud e that the se arated clay is freed of adsor d acid slu ge constituents before calcination.

I have found that by washing the clay with 'sufiicient quantities of hot or cold water, by intimately commingling the clay and the water, substantially all of the acid sludge can be removed from the clay so that on subsequent calcination the clay is restored to its original, and even improved efficiency. The water wash removes more than merely the inorganic acid which the clay adsorbs on treating the acid treated oil, it also removes the reaction products of the acid with the oil, namely the acid sludge which is adsorbed by the clay. The water wash also removes re- :of the clay. As a ticles, is treated with decolori'zing' clay w ch without completely destroying its efliciency.

- t I new as 4w. Is

as products of the acid and ms constituentsofthe clay whichon i ition form poisons decreasing the adsorptive efliciency rticular illustretion'ofthemannerin which may carry out my inventiomacid oil, for instanoe, linewhich has been sold treated and w ich contains acid sludge arwill both decolorize the gasoline and remove the acid sludge particles. This clay can be revivified by simple i ition and used again, and perhaps revivifi and used a second time. Butit cannot be revivified many more times However, it this clay is de-oiled by heating to a simmering temperature, i. e. 205 212 F. and the oil floated off and the clay washed thoroughly, by violent agitation or boiling, to remove substantially all of the acid sludge in the clay before it is calcined or ignited it can then be re-calcined and reused many more times than, if this intermediate sludge removal stage is not employed; The de-oiling and washing of the clay can be combined into j one continuous process by first adding the necessary amount of water, either hot or cold, i. e. about five times the weight of the dry clay, heating the mixture to a simmering tem-- perature, skimming oil the oil which has thus been oausedto rise to the surface and then after the greater part of the oil has been removed, completing the washing by boiling the mixture stron ly for about ten minutes. The clay can then settled or filtered.

The washed clay is then dried and ignited at about 1200 F. until free from visible carwater as possible. A filter may be used in adsor place "of'the eentrifu e and the wash water passed through the ca e.

The de-oiled and washed clay is then dried and ignited as described above.

The above description is not to be taken as limiting m invention, but is merely illustrative of t e best method of carrying it out, As will b nnderstoo'dj'by those skilled inthe art, manymodificntions can be made within the s irit of my invention which I claim to'be TOWBSLOf reviiiiiying"clay-containin (1 acid sludge resulting from the treating of oils which have been the'niselves'trezit'efl with acid, which comprises washing the c lg y H with water in sufiicient'qnantiti'es tfi'ienioi e" i r ubstantia ly ll the, ci slud an 0 m di 'vni'i i i tsfir xhlt c'li t demen ia, IQiniI g he iY QrQ y same.

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